US7116564B2 - Switching power supply unit and semiconductor device for switching power supply - Google Patents

Switching power supply unit and semiconductor device for switching power supply Download PDF

Info

Publication number
US7116564B2
US7116564B2 US11/180,702 US18070205A US7116564B2 US 7116564 B2 US7116564 B2 US 7116564B2 US 18070205 A US18070205 A US 18070205A US 7116564 B2 US7116564 B2 US 7116564B2
Authority
US
United States
Prior art keywords
signal
current
voltage
feedback signal
control circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US11/180,702
Other languages
English (en)
Other versions
US20060018136A1 (en
Inventor
Satoru Takahashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Collabo Innovations Inc
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Assigned to MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. reassignment MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TAKAHASHI, SATORU
Publication of US20060018136A1 publication Critical patent/US20060018136A1/en
Application granted granted Critical
Publication of US7116564B2 publication Critical patent/US7116564B2/en
Assigned to PANASONIC CORPORATION reassignment PANASONIC CORPORATION CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
Assigned to PANASONIC CORPORATION reassignment PANASONIC CORPORATION LIEN (SEE DOCUMENT FOR DETAILS). Assignors: COLLABO INNOVATIONS, INC.
Assigned to COLLABO INNOVATIONS, INC. reassignment COLLABO INNOVATIONS, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: PANASONIC CORPORATION
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0006—Arrangements for supplying an adequate voltage to the control circuit of converters

Definitions

  • the present invention relates to a switching power supply unit having an overload protecting function and an overcurrent protecting function and to a semiconductor device used for the switching power supply unit.
  • FIG. 8 is a circuit diagram of an example of conventional switching power supply units.
  • reference numeral 130 denotes a semiconductor device for controlling the switching power supply.
  • the semiconductor device 130 includes a switching device 101 and its control circuit.
  • the semiconductor device 130 is provided with the input terminal (DRAIN) of the switching device 101 , an auxiliary power supply voltage input terminal (VCC), an internal circuit power supply terminal (VDD), a feedback signal input terminal (FB), the output terminal of the switching device 101 , and the GND terminal (GND) of the control circuit as external input terminals.
  • VCC auxiliary power supply voltage input terminal
  • VDD internal circuit power supply terminal
  • FB feedback signal input terminal
  • GND GND terminal
  • Reference numeral 102 is a regulator which supplies the internal circuit power supply of the semiconductor device 130 .
  • the regulator is provided with a switch 102 A, which flows a starting current into VCC, and a switch 102 B which supplies the current from VCC to VDD.
  • Reference numeral 103 denotes a start-up constant current source which supplies a start-up circuit current.
  • the constant current source supplies the starting current to VCC via the switch 102 A during start up.
  • Reference numeral 107 denotes a start-up and shut-down circuit which controls the start up and the shut down of the semiconductor device 130 .
  • the start-up and shut-down circuit detects voltage at VCC and outputs a signal which stops the switching operation of the switching device 101 to a NAND circuit 105 when voltage at VDD is below a constant voltage.
  • Reference numeral 106 denotes a drain current detection circuit which detects a current flowing into the switching device 101 through the detection of the on voltage at the switching device 101 generated by the product of the current flowing into the switching device 101 and the on resistance of the switching device 101 and which converts the detected current value of the switching device 101 to a voltage signal to output the voltage signal to a comparator 108 according to the current value of the switching device 101 .
  • Reference numeral 111 denotes a feedback signal control circuit which converts a current signal inputted to the FB terminal to a voltage signal to output the signal to the comparator 108 .
  • the comparator 108 outputs a signal to the reset terminal of a RS flip-flop circuit 110 when the output signal from the feedback signal control circuit 111 becomes equal to the output signal from the drain current detection circuit 106 .
  • Reference numeral 112 denotes a clamp circuit which determines the maximum value of the output signal of the feedback signal control circuit 111 . Since the clamp circuit 112 determines the maximum value of the current flowing into the switching device 101 , the clamp circuit 112 has the function of protecting the switching device 101 from overcurrent and limits the maximum value of the primary drain current, which limits a maximum power to be supplied to a secondary load and determines an overload protection level.
  • Reference numeral 109 denotes an oscillation circuit, which outputs a maximum duty-cycle signal 109 A, which determines the maximum duty cycle of the switching device, 101 , and a clock signal 109 B which determines the oscillation frequency of the switching device 101 .
  • the maximum duty-cycle signal 109 A is input to the NAND circuit 105
  • the clock signal 109 B is input to the set terminal of the RS flip-flop circuit 110 .
  • the output signal of the start-up and shut-down circuit 107 , the maximum duty-cycle signal 109 A, and an output signal of the RS flip-flop circuit 110 are input to the NAND circuit 105 .
  • the output signal of the NAND circuit 105 is input to a gate drive circuit 104 to control the switching operation of the switching device 101 .
  • Reference numeral 140 denotes a transformer, which has a primary winding 140 A, a secondary winding 140 B, and a primary auxiliary winding 140 C.
  • a rectifying-smoothing circuit composed of a diode 131 and a capacitor 132 is connected to the primary auxiliary winding 140 C and is used as the auxiliary power supply section of the semiconductor device 130 used for input to VCC.
  • Reference numeral 133 denotes a capacitor for stabilizing VDD.
  • Reference numeral 135 denotes a control signal transmission circuit which transmits a control signal from the secondary side to the primary side and which is composed of a phototransistor 135 A and a photodiode 135 B.
  • the collector of the phototransistor 135 A is connected to FB, and the emitter of the phototransistor 135 A is connected to GND.
  • a rectifying-smoothing circuit composed of a diode 150 and a capacitor 151 is connected to the secondary winding 140 B and is further connected to the photodiode 135 B, a secondary control circuit 158 , and a load 157 .
  • the secondary control circuit 158 includes a shunt regulator 152 , resistors 154 , 155 , and 156 , and a capacitor 153 , supplies a voltage divided by the resistors 154 and 155 for detecting secondary output voltage VO to the reference terminal of the shunt regulator 152 , and controls a current which flows into the photodiode 135 B connected to the cathode of the shunt regulator so as to keep the secondary output voltage VO constant.
  • FIG. 9 is a time chart of the operation waveform of each section shown in FIG. 8 .
  • a direct-current voltage VIN formed by rectifying and smoothing commercial alternating-current power supply voltage, for instance, is supplied to the input terminal.
  • VIN is applied to the DRAIN terminal of the semiconductor device 130 via the primary winding 140 A of the transformer 140 .
  • a starting current formed at the start-up constant current source 103 flows to charge the capacitor 132 connected to VCC via the switch 102 A of the regulator 102 , thereby the voltage at VCC is raised.
  • the switch 102 B of the regulator 102 operates so as to make the voltage at VDD constant, the capacitor 133 connected to VDD via the switch 102 B is charged by part of the starting current, thereby the voltage at VDD is also raised.
  • the current flowing through the secondary winding 140 B is rectified by the diode 150 and smoothed by the capacitor 151 into a direct-current power, so that the power is supplied to the load 157 .
  • the output voltage VO rises gradually through the switching operation repeated.
  • the output voltage VO reaches a voltage set by the output voltage detecting resistors 154 and 155 , the current which flows into the photodiode 135 B is increased by a signal from the secondary control circuit 158 .
  • the current flowing into the primary auxiliary winding 140 is rectified by the diode 131 and smoothed by the capacitor 132 . Moreover, the current is utilized as an auxiliary power for the semiconductor device 130 to be supplied to the VCC terminal.
  • the switch 102 A of the regulator 102 is turned OFF, so that the current of the semiconductor device after the starting is supplied from the primary auxiliary winding 140 C. Since the polarity of the primary auxiliary winding 140 C is the same as that of the secondary winding 140 B, the voltage at VCC is proportional to the output voltage VO.
  • the maximum value of the primary drain current is fixed, so that a maximum power suppliable to the secondary load is limited.
  • ILIMIT maximum power limited under peak load
  • FIG. 10 is a circuit diagram of another conventional switching power supply unit having an overload protecting function as a power supply.
  • FIG. 10 is different from FIG. 8 in that an output current detection resistor 159 , an overcurrent detection circuit 160 , an overcurrent signal transmission circuit 136 are provided.
  • an output current IO exceeds a constant value, the current flowing into a photodiode 136 B increases, and then the current flows from a power supply voltage terminal VDD into GND via a phototransistor 136 A.
  • the voltage at the VDD terminal decreases, a stop signal is output from a start-up and shut-down circuit 107 , the switching operation of a switching device 101 stops, and the overload protecting function operates as the power supply, so that it becomes possible to realize the overload protecting function as the power supply when its drain current is smaller than ILIMIT. That is, when a time delay is provided for the detection at the overcurrent detection circuit 160 , the protection against the peak load can be gained by ILIMIT, and the overload protection during normal operation can be gained by the drain current smaller than ILIMIT. In the configuration shown in FIG. 10 , however, the element count increases inevitably.
  • An object of the present invention is to provide a switching power supply unit and a semiconductor device for the switching power supply unit which have no increase in component count, entail no increase in production cost, have no complex circuit configuration as a power supply, and are capable of achieving overload protection under normal load and overcurrent protection against peak load.
  • the switching power supply unit according to the invention is a switching power supply unit which does output through the conversion of an inputted first direct-current voltage to a second direct-current voltage via a transformer.
  • the switching power supply unit is provided with a switching device, an output voltage control circuit, a control signal transmission circuit, and a control circuit.
  • the switching device is connected to the primary side of the transformer to which the first direct-current voltage is applied.
  • the output voltage control circuit stabilizes the second direct-current voltage.
  • the control signal transmission circuit transmits a signal from the output voltage control circuit to the primary side of the transformer.
  • the control circuit controls the operation of the switching device.
  • the control circuit has a switching device current detection circuit, a feedback signal control circuit, a comparator, a switching signal control circuit, a clamp circuit, an overload protection delay time control circuit, a capacitor for adjusting overload protecting operation delay time, and an overload signal output circuit.
  • the switching device current detection circuit detects a signal flowing through the switching device and outputs the current as a device current detecting signal.
  • the feedback signal control circuit receives the signal from the control signal transmission circuit as a feedback signal, outputs a feedback output signal varying according to the feedback signal, and outputs a charging start signal for overload protection when the feedback signal reaches a specified feedback signal level.
  • the comparator compares the output signal from the switching device current detection circuit with the feedback output signal and outputs the comparison signal thus produced.
  • the switching signal control circuit controls the amount of the current and the output of the switching device based on the comparison signal.
  • the clamp circuit fixes the maximum value of the feedback output signal and limits the maximum value of the current of the switching device.
  • the overload protection delay time control circuit receives the charging start signal for the overload protection as input and supplies a charging current.
  • the capacitor for adjusting overload protecting operation delay time is charged with the charging current of the overload protection delay time control circuit.
  • the overload signal output circuit detects the voltage at the capacitor for adjusting the overload protection delay time and outputs a switching shut-down signal when the voltage exceeds a specified voltage.
  • the switching signal control circuit controls the peak value of the current of the switching device according to the feedback signal to the feedback signal control circuit and stops the operation of the switching device based on the switching shut-down signal from the overload signal output circuit.
  • the signal from the secondary control circuit is transmitted as the feedback signal to the input terminal of one feedback signal control circuit via one control signal transmission circuit, the peak value of the current of the primary switching device is controlled according to the feedback signal, so that the overload protection against the normal load and the overcurrent protection against the peak load can be realized concurrently and readily by the signal transmitted to the primary side through the same control signal transmission circuit.
  • the protecting operation delay time until the stop of the switching operation through the overload protecting operation can be freely adjusted by an external capacitor, it is possible to deal with the wide-ranging peak load irrespective of the load level thereof.
  • an output voltage generation circuit and an auxiliary power supply voltage generation circuit is further included.
  • the output voltage generation circuit is connected to the secondary winding of the transformer, generates the second direct-current voltage whose absolute value is smaller than that of the first direct-current voltage from the first direct-current voltage through the rectification and smoothing of the secondary output voltage at the transformer, and outputs the second direct-current voltage
  • the auxiliary power supply voltage generation circuit is connected to the auxiliary winding of the transformer, generates primary output voltage, and rectifies and smooths the generated primary output voltage to generate the auxiliary power supply voltage used as the power supply voltage for the control circuit.
  • control signal transmission circuit transmits the signal from the output voltage control circuit to the primary side of the transformer in one system.
  • the feedback signal at the time when the feedback output signal starts to be fixed at a maximum value corresponds to a first feedback signal level
  • a current which is able to flow to the switching device at the first feedback signal level becomes maximum
  • the first feedback signal level and the specified feedback signal level are set in a manner that a current smaller than the maximum current which is able to flow flows into the switching device.
  • the feedback signal control circuit included in the configuration is provided with a constant current source for detecting the specified feedback signal level used for detecting the feedback signal which has reached the specified feedback signal level and outputs the charging start signal for the overload protection through the comparison of the current value of the constant current source for detecting the specified feedback signal level and the current value proportional to the feedback signal.
  • the feedback signal control circuit is provided with a charging start detection comparator for the overload protection which compares the feedback output signal and a charging start detecting reference voltage source for the overload protection specified therein and which outputs the charging start signal for protecting the overload protection when the comparator has detected the specified feedback signal level as the feedback output signal.
  • the feedback signal control circuit included in the configuration is provided with a light-load mode detection comparator, which compares the feedback output signal and a light-load reference voltage source specified therein, and performs the current peak control and the intermittent operation of the switching device according to the feedback signal to the feedback signal control circuit.
  • control circuit is further provided with an oscillator which generates and outputs a switching signal applied to the switching device.
  • the overload signal output circuit outputs the switching operation stop signal through the detection of a rise in the voltage at the capacitor for adjusting the overload protection delay time to a first specified voltage and outputs a signal which restarts the switching operation of the switching device through the detection of a decrease in the voltage at the capacitor for adjusting the overload protection delay time below a second specified voltage.
  • the overload protection delay time control circuit stops charging to the capacitor for adjusting the overload protecting operation delay time to keep a state where discharge current is flowed for a fixed time period.
  • the overload signal output circuit outputs the switching operation stop signal in a latch mode through the rise in the voltage at the capacitor for adjusting the overload protection delay time to the specified voltage.
  • the semiconductor device for the switching power supply according to the invention is a semiconductor device which has a control circuit and is used for the switching power supply unit which comprises:
  • the switching device connected to the primary side of the transformer to which the first direct-current voltage is input;
  • the output voltage control circuit which stabilizes the second direct-current voltage to become an output of the secondary side of the transformer
  • control signal transmission circuit which transmits the signal from the output voltage control circuit to the primary side of the transformer
  • control circuit which controls the operation of the switching device.
  • the control circuit has the switching device current detection circuit, the feedback signal control circuit, the comparator, the switching signal control circuit, the clamp circuit, the overload protection delay time control circuit, the capacitor for adjusting the overload protecting operation delay time, and the overload signal output circuit.
  • the switching device current detection circuit detects the current flowing through the switching device to output the current as the device current detection signal.
  • the feedback signal control circuit receives the signal from the control signal transmission circuit as the feedback signal, outputs the feedback output signal varying in response to the feedback signal, and outputs the charging start signal for the overload protection when the feedback signal has reached the specified feedback signal level.
  • the comparator compares the output signal from the switching device current detection circuit and the feedback output signal to output the comparison signal thus produced.
  • the switching signal control circuit controls the amount of the current and the output of the switching device based on the comparison signal.
  • the clamp circuit fixes the maximum value of the feedback output signal to limit the maximum value of the current of the switching device.
  • the overload protection delay time control circuit receives the charging start signal for the overload protection as the input to supply the charge current.
  • the capacitor for adjusting the overload protecting operation delay time is charged with the charge current of the overload protection delay time control circuit.
  • the overload signal output circuit detects the voltage at the capacitor for adjusting the overload protecting operation delay time and outputs the switching stop signal when the voltage has exceeded the specified voltage.
  • the switching signal control circuit controls the peak value of the current of the switching device according to the feedback signal to the feedback signal control circuit and stops the operation of the switching device based on the switching stop signal of the overload signal output circuit.
  • the feedback signal at the time when the feedback output signal starts to be fixed at a maximum value corresponds to a first feedback signal level
  • a current which is able to flow into the switching device at the first feedback signal level becomes maximum
  • the first feedback signal level and the specified feedback signal level are set in a manner that a current smaller than the maximum current which is able to flow flows into the switching device.
  • the absolute value of the current of the feedback signal at the first feedback signal level is smaller than that of the current of the feedback signal at the specified feedback signal level.
  • the feedback signal control circuit included in the configuration is provided with the constant current source for detecting the specified feedback signal level used for detecting the feedback signal which has reached the specified feedback signal level and outputs the charging start signal for the overload protection through the comparison of the current value of the constant current source for detecting the specified feedback signal level and the current value proportional to the feedback signal.
  • the feedback signal control circuit included in the configuration is provided with the charging start detection comparator for the overload protection which compares the feedback output signal and the charging start detecting reference voltage source for the overload protection specified therein and which outputs the charging start signal for the overload protection when the comparator has detected the specified feedback signal level as the feedback output signal.
  • the feedback signal control circuit included in the configuration is provided with the light-load mode detection comparator, which compares the feedback output signal and the light-load reference voltage source specified therein, and performs the current peak control and the intermittent operation of the switching device according to the feedback signal to the feedback signal control circuit.
  • the control circuit included in the configuration is further provided with the oscillator which generates and outputs the switching signal applied to the switching device.
  • the overload signal output circuit included in the configuration outputs the switching operation stop signal through the detection of the rise in the voltage at the capacitor for adjusting the overload protection delay time to the first specified voltage, and detects the decrease in the voltage at the capacitor for adjusting the overload protection delay time below the second specified voltage to output the output signal which restarts the switching operation of the switching device.
  • the overload protection delay time control circuit stops the charging to the capacitor for adjusting the overload protecting operation delay time to keep the state in which the discharge current is flowed for the fixed time period.
  • the overload signal output circuit included in the configuration outputs the switching operation stop signal in the latch mode through the rise in the voltage at the capacitor for adjusting the overload protection delay time to the specified voltage.
  • the switching device and the control circuit are formed on the same semiconductor substrate.
  • FIG. 1 is a circuit diagram of a switching power supply unit according to a first embodiment of the present invention
  • FIG. 2 is a circuit diagram of a semiconductor device included in the switching power supply unit according to the first embodiment of the invention
  • FIG. 3 is a graph for explaining the dependence of a switching device current and a capacitor for adjusting overload protection delay time on feedback current of the switching power supply unit of the invention
  • FIG. 4 is a time chart for explaining operations of the switching power supply unit of the invention under light load and overload;
  • FIG. 5 is a time chart for explaining operations of the switching power supply unit of the invention under peak load
  • FIG. 6 is a circuit diagram of a semiconductor device included in a switching power supply unit according to a second embodiment of the invention.
  • FIG. 7 is a circuit diagram of a semiconductor device included in a switching power supply unit according to a third embodiment of the invention.
  • FIG. 8 is a circuit diagram of a conventional switching power supply init
  • FIG. 9 is a time chart for explaining operations of the conventional switching power supply unit.
  • FIG. 10 is a circuit diagram of another conventional switching power supply unit.
  • FIG. 1 is a circuit diagram of a switching power supply unit and a semiconductor device according to a first embodiment of the invention.
  • FIG. 2 is a detailed circuit diagram for explaining the configuration of the semiconductor device 30 for controlling the switching power supply shown in FIG. 1 .
  • reference numeral 30 denotes the semiconductor device for controlling the switching power supply.
  • the semiconductor device 30 includes a switching device 1 and its control circuit.
  • the semiconductor device 30 is provided with the input terminal (DRAIN) of the switching device 1 , an auxiliary power supply voltage input terminal (VCC), an internal circuit power supply terminal (VDD), a feedback signal input terminal (FB), a capacitor connecting terminal (OL) for adjusting the delay time of overload protecting operation, the output terminal of the switching device 1 , and the GND terminal (GND) of the control circuit as external input terminals.
  • VCC auxiliary power supply voltage input terminal
  • VDD internal circuit power supply terminal
  • FB feedback signal input terminal
  • OLED capacitor connecting terminal
  • Reference numeral 2 is a regulator which supplies internal circuit power supply of the semiconductor device 30 .
  • the regulator is provided with a switch 2 A which flows starting current to VCC and a switch 2 B which supplies the current from VCC to VDD.
  • the switch 2 A is in the ON state until voltage at VCC reaches a constant voltage to supply the starting current to VCC.
  • the switch 2 B supplies the current from VCC to VDD until potential at VDD reaches a constant potential.
  • VDD is held at the constant potential by stopping the supply of the current.
  • Reference numeral 3 is a start-up constant current source which supplies circuit current for starting.
  • the start-up constant current source 3 supplies the starting current to VCC via the switch 2 A at the time of start up.
  • Reference numeral 7 is a start-up and shut-down circuit which controls the start up and the shut down of the semiconductor device 30 .
  • the start-up and shut-down circuit 7 detects voltage at VDD and outputs a signal which stops the switching operation of the switching device 1 to a NAND circuit 5 when the voltage at VDD is below a constant voltage. Also, the start-up and shut-down circuit 7 controls the switches 2 A and 2 B as described above.
  • a “L” signal is output from the start-up and shut-down circuit 7 to the NAND circuit 5 . Thereafter, a “H” signal is input to a gate driver 4 , and then a “L” signal is output from the gate driver 4 , thereby the switching operation of the switching device 1 is stopped.
  • Reference numeral 6 is a drain current detection circuit which detects current flowing into the switching device 1 .
  • the detected signal is converted to a voltage signal, and then the signal is output to a comparator 8 .
  • Reference numeral 11 is a feedback signal control circuit, which converts a current signal IFB flowing out of the FB terminal to a voltage signal to output the signal to the comparator 8 .
  • the comparator 8 outputs the signal to the reset terminal of a RS flip-flop circuit 10 when the output signal from the feedback signal control circuit 11 has become equal to the output signal from the drain current detection circuit 6 .
  • the signal is processed in a manner that the reset signal is output to the reset terminal of the RS flip-flop circuit 10 , and the switching device 1 is turned OFF via the NAND circuit 5 and the gate driver circuit 4 .
  • the gate driver circuit 4 , the NAND circuit 5 , and the RS flip-flop circuit 10 is included in a switching signal control circuit which controls the switching device 1 .
  • Reference numeral 12 is a clamp circuit which determines the maximum value of the output signal VFBO of the feedback signal control circuit 11 which varies according to the feedback current (IFB).
  • the clamp circuit determines the maximum value (ILIMIT) of the current flowing into the switching device 1 and has the function of protecting the overcurrent at the switching device 1 .
  • the feedback current at the time when IFB varies and the current flowing into the switching device 1 reaches ILIMIT is a first feedback current (IFB 1 ) (see FIG. 3 ).
  • Reference numeral 14 is an overload protection delay time control circuit.
  • the overload protection delay time control circuit 14 detects the feedback current which has reached a second feedback current (IFB 2 ), receives a charging start current for the overload protection outputted from the feedback signal control circuit 11 as an input signal to one side of a NAND circuit 14 S as shown in FIG. 2 , and receives a starting signal (UV) of the start-up and shut-down circuit 7 as a signal to the other side of the NAND circuit 14 S. thereafter, when the feedback current reaches IFB 2 in the starting state in which the switching device 1 is performing the switching operation, charging current is supplied to a capacitor 34 (COL) for adjusting the overload protecting operation delay time.
  • the peak current of the switching device 1 (IDP 2 ) during the feedback effected by the start of the charging to COL 34 is set in a manner that the value of IDP 2 becomes smaller than the maximum value of the current flowing into the switching device (ILIMIT).
  • Reference numeral 13 is the overload signal output circuit.
  • the overload signal output circuit 13 When voltage at the connecting terminal (OL) of the capacitor for adjusting the overload protecting operation delay time connected to the capacitor for adjusting the overload protecting operation delay time 34 (COL) exceeds a constant voltage, the overload signal output circuit 13 outputs the overload signal (VOLP) to the start-up and shut-down circuit 7 to stop the switching operation of the switching device 1 . Also, when the switching stops concurrently, the starting signal (UV) is inverted, the output signal of the NAND circuit 14 S becomes “H”, and the charging current to the capacitor for adjusting the overload protecting operation delay time 34 (COL) is shut down, thereby the charge of COL 34 is discharged.
  • FIG. 3 is a graph explaining a relationship between the feedback current IFB and the peak current IDP flowing into the switching device 1 , a relationship between IFB 1 –IFB 2 and ILIMIT-IDP 2 , and a relationship between IFB and a charge-discharge state IOL.
  • Reference numeral 17 is a light-load detecting comparator, to which a light-load reference voltage source 18 is connected as reference voltage VR.
  • the comparator 17 is set so as to output a “L” signal when the drain current peak value of the switching device 1 decreases to about 15% of the overcurrent protection level ILIMIT and to output a “H” signal so that the drain current recover to about 20% of ILIMIT. That is, the light-load reference voltage source 18 outputs either of the two voltages in response to the output of the comparator.
  • Reference numeral 9 is an oscillation circuit, which outputs a maximum duty-cycle signal 9 A, which determines the maximum duty cycle of the switching device 1 , and a clock signal 9 B which determines the oscillation frequency of the switching device 1 .
  • the maximum duty-cycle signal 9 A is input to the NAND circuit 5
  • the clock signal 9 B is input to an AND circuit 16 .
  • the output signal of the light-load detecting comparator 17 and the clock signal 9 B from the oscillation circuit 9 are input to the AND circuit 16 , and the AND circuit 16 outputs a signal to the set terminal of the RS flip-flop circuit 10 . That is, only when the signal from the light-load detecting comparator 17 is a “H”, the clock signal 9 B is input to the set terminal of the RS flip-flop circuit 10 .
  • the output signal of the start-up and shut-down circuit 7 , the maximum duty-cycle signal 9 A, and the output signal of the RS flip-flop circuit 10 are input to the NAND circuit 5 .
  • the output signal of the NAND circuit 5 is input to the gate drive circuit 4 to control the switching operation of the switching device 1 .
  • Reference numeral 40 is a transformer, which has a primary winding 40 A, a secondary winding 40 B, and a primary auxiliary winding 40 C.
  • a rectifying-smoothing circuit composed of a diode 31 and a capacitor 32 is connected to the primary auxiliary winding 40 C.
  • the primary auxiliary winding 40 C is used as the auxiliary power supply section of the semiconductor device 30 , and the power of the auxiliary power supply section is input to VCC.
  • Reference numeral 33 is a capacitor for stabilizing VDD.
  • Reference numeral 35 is a control signal transmission circuit, which transmits a control signal from the secondary side to the primary side.
  • the control signal at the secondary side can be detected relatively easily by using a plurality of transmission circuits.
  • such a configuration becomes complex as a power supply unit and causes increases in element count and production cost.
  • such problems are solved by handling two controls through the use of one transmission circuit.
  • the control signal transmission circuit 35 includes a phototransistor 35 A and a photodiode 35 B.
  • the collector of the phototransistor 35 A is connected to the terminal VDD, and the emitter of the phototransistor 35 A is connected to the terminal FB.
  • a rectifying-smoothing circuit composed of a diode 50 and a capacitor 51 is connected to the second winding 40 B, and then the second winding 40 B is connected to the photodiode 35 B, a secondary control circuit 58 , and a load 57 .
  • the secondary control circuit 58 includes a shunt regulator 52 , resistors 54 , 55 , and 56 , and a capacitor 53 , inputs voltage divided by the resistors 54 and 55 for detecting secondary output voltage VO to the reference terminal of the shunt regulator 52 , and controls current which flows into the photodiode 35 B connected to the cathode of the shunt regulator 52 in a manner that the secondary output voltage VO becomes constant.
  • FIG. 4 is a time chart of the operation waveform of each section shown in FIG. 1 under light load
  • FIG. 5 is a time chart of the operation waveform of each section shown in FIG. 1 under peak load.
  • direct-current voltage VIN produced by rectifying and smoothing commercial alternating-current power supply, for instance, is input to the input terminal.
  • VIN is applied to the drain terminal of the semiconductor device 30 via the primary winding 40 A of the transformer 40 .
  • the starting current produced at the start-up constant current source 3 flows to charge the capacitor 32 connected to VCC via the switch 2 A of the regulator 2 , thereby the voltage at VCC is raised.
  • the switch 2 B of the regulator 2 operates in a manner that the voltage at VDD becomes constant, the capacitor 33 connected to VDD via the switch 2 B is charged by part of the starting current, thereby the voltage at VDD is also raised.
  • the switching operation of the switching device 1 is started.
  • energy is supplied to each winding of the transformer 40 , so that a current flows into the secondary wiring 40 B and the primary auxiliary winding 40 C.
  • the current which has passed through the secondary winding 40 B is rectified by the diode 50 and smoothed by the capacitor 51 into direct-current power, and then the power is supplied to the load 57 .
  • the output voltage VO rises gradually through the repeated switching.
  • the output voltage VO reaches the voltage set by the output voltage detecting resistors 54 and 55 , the current which flows into the photodiode 35 B increases through the transmission of signals from the secondary control circuit 58 . Thereafter, current which flows into the phototransistor 35 A increase, and current which flows into the FB terminal also increases.
  • the output voltage VO decreases, the decrease in the output voltage VO is detected by the resistance division of the resistors 54 and 55 of the secondary control circuit 58 , a voltage which is proportionate to the output voltage is input to the reference terminal of the shunt regulator 52 , the current flowing into the photodiode 35 B decreases, and finally no current flows to the photodiode 35 B to decrease the feedback current flowing via the phototransistor 35 A.
  • IFB reaches the second feedback current (IFB 2 )
  • the charging current (IOL) is supplied to the capacitor 34 (COL) for adjusting the overload protecting operation delay time.
  • VOL OL terminal voltage
  • the signal VOLP is output from the overload signal output circuit 13 to stop the switching operation.
  • the signal VOLP is input to the start-up and shut-down circuit 7 , after which the signal is output from the start-up and shut-down circuit 7 to stop the switching operation.
  • a signal for forcedly discharging the OL terminal is also concurrently transmitted from the start-up and shut-down circuit 7 to the overload protection delay time control circuit 14 , so that the OL terminal voltage decreases.
  • the charging time of the capacitor 34 i.e., the rise time of the voltage VOL
  • the capacitance of the capacitor 34 for adjusting the overload protection delay time it becomes possible to freely set a delay time between the beginning of the overload state and the actual stop of the switching operation trough the overload protecting operation.
  • the output voltage VO decrease, and then the decrease in the output voltage VO is detected by the resistive division of the resistors 54 and 55 of the secondary control circuit 58 , following which a voltage proportionate to the output voltage is input to the reference terminal of the shunt regulator 52 . Furthermore, the current flowing into the photodiode 35 B decreases, and finally no current flows into the photodiode 35 B. Then, the feedback current IFB flowing via the phototransistor 35 A decreases, the switching device current increases according to IFB, and the current being at the overcurrent protection level ILIMIT flows at its maximum. When IFB has reached the second feedback current IFB 2 before reaching ILIMIT, the charging current IOL starts to be supplied to the capacitor 34 for adjusting overload protecting operation delay time, thereby the OL terminal voltage VOL is increased.
  • the switching operation does not stop for a time period for which the OL terminal voltage VOL determined by the selection of the capacitor 34 for adjusting overload protecting operation delay time and the charging current IOL to the capacitor 34 rises to the specified voltage VOLS, so that it is possible to not only deal with the peak load, but keep the output voltage VO at a normal value. Therefore the duration of the peak load can be adjusted by freely selecting the capacitor 34 for adjusting overload protecting operation delay time.
  • the secondary control circuit 58 detects a miniscule rise in the output voltage VO, and the reference terminal voltage of the shunt regulator 52 rises. Because of this, drawing current from the cathode of the shunt regulator 52 increases, the current flowing trough the photocoupler 35 B increases, and the FB terminal current IFB increases via the phototransistor 35 A.
  • the output voltage VFBO of the feedback signal control circuit 11 decreases, and the peak value of the drain current IDS flowing through the switching device 1 gradually decreases. Furthermore, when the load has been reduced, IFB further decreases, the output voltage VFBO decreases, and the peak value of the drain current IDS also decreases further.
  • IFB increases further.
  • the “L” signal is output from the light-load mode detecting comparator 17 , thereby the switching operation is stopped to shift to a light-load stop state.
  • the light-load reference voltage source 18 changes its voltage to a light-load upper-limit voltage VR 2 .
  • the secondary control circuit 58 detects a miniscule fall in the output voltage VO, and the reference terminal voltage of the shunt regulator 52 drops, so that the drawing current from the cathode of the shunt regulator 52 decreases. Furthermore, the current flowing through the photocoupler 35 B decreases, the FB current IFB decreases via the phototransistor 35 A, and the output voltage VFBO of the feedback signal control circuit 11 rises. When the output voltage VFBO has reached the light-load upper-limit voltage VR 2 , the switching operation is restarted. So long as the light-load state and the no-load state continue, such an operation is repeated; that is, in the switching operation of the switching device 1 , the intermittent operation is effected where the durations of the switching operation and the stop of the switching operation are repeated alternately.
  • the value of the light-load reference voltage source is set in a manner that the peak value of the drain current at the time of the shift from the switching operation to the light-load stop state is set at about 15% of the overcurrent protection level ILIMIT determined by the clamp circuit, and the peak value of the drain current at the time of the shift from the light-load stop state to the operation state is set at about 20% of ILIMIT.
  • FIG. 2 is a circuit diagram of a semiconductor device for controlling a switching power supply included in the switching power supply unit according to the invention.
  • the internal circuit of the semiconductor device 30 shown in FIG. 1 is illustrated in detail, and since the reference numerals shown in FIG. 2 correspond with those shown in FIG. 1 , the explanation of the same member is omitted.
  • the feedback signal control circuit 11 includes a constant current source 11 R, N-type MOSFETs 11 A, 11 B, and 11 C, and a resistor 11 P.
  • the output signal VFBO of the feedback signal control circuit 11 decreases, so that the peak value of the drain current of the switching device 1 decreases.
  • the output signal VFBO of the feedback signal control circuit 11 increases, so that the switching device 1 operates to increase the peak value of the drain current.
  • the clamp circuit 12 includes a P-type MOSFET 12 A, a constant current source 12 B, and a resistor 12 C.
  • the clamp circuit 12 operates so as to clamp VFBO with a voltage generated by the product of a current supplied from the constant current source 12 B and the resistance of the resistor 12 C and with a voltage determined by the sum of the potentials at the gate and the source of the P-type MOSFET 12 A.
  • the clamping voltage of the clamp circuit 12 determines the maximum current of the switching device 1 , i.e., the overcurrent protection level ILIMIT.
  • IFB at the time when VFBO increases through the decrease in IFB and just reaches the clamp voltage, that is, VFBO reaches the maximum current ILIMIT of the switching device 1 is IFB 1 .
  • the increase in the feedback current IFB brings about the decrease in the output signal VFBO of the feedback signal control circuit 11 , and furthermore, when the output signal VFBO of the feedback signal control circuit 11 decreases to the reference voltage VR of the light-load reference voltage source 18 , the “L” signal is output from the light-load mode detection comparator 17 to the AND circuit 16 , and the “L” signal is input to the set terminal of the RS flip flop 10 , thereby the switching operation of the switching device 1 is stopped.
  • IFB 2 is defined as IFB at the time when IFB decreases, and then the “H” signal is output from the feedback signal control circuit 11 to the overload protection delay time control circuit 14 as described above.
  • IDP 2 is defined as the current of the switching device 1 at the time when IFB reaches IFB 2 .
  • IFB 1 and IFB 2 have a relationship IFB 1 ⁇ IFB 2
  • ILIMIT and IDP 2 have a relationship ILIMIT>IDP 2 .
  • the overload protection delay time control circuit 14 includes the NAND circuit 14 S, a P-type MOSFET 14 J, a N-type MOSFET 14 Q, and a constant current source 14 R.
  • the overload signal output circuit 13 includes a comparator 13 A, resistors 13 B and 13 C, and a reference voltage source 13 D and detects a rise in the voltage VOL at the terminal OL to which the capacitor 34 (COL) is connected.
  • VOL rises until voltage divided by the resistors 13 B and 13 C becomes equal to the voltage of the reference voltage source 13 D
  • the “H” overload stop signal VOLP is output from the comparator 13 A.
  • the signal VOLP is input to the start-up and shut-down circuit 7 , thereby the shift to the overload protection stop state is effected to stop the switching operation.
  • VOL rises to the specified voltage VOLS, so that the overload protecting operation is effected to stop the switching operation.
  • the switching operation is not stopped immediately.
  • the switching operation can be performed for a fixed time period and can be continued until the peak load state is reached.
  • TOLP the delay time taken until the overload protecting operation is stopped
  • the overload protection delay time can be freely selected by determining the capacitance of the capacitor 34 freely.
  • the time taken for a measure against the peak load can be also selected.
  • the points of the overload protecting operation under the normal load and of the measure against the peak load can be set internally by determining the relationship between IDP 2 and ILIMIT.
  • ILIMIT is set at 120% of IDP 2 , it becomes possible to supply for a fixed time period the primary switching device current 20% larger than that at the point when the overload protecting operation is effected under normal load, which facilitates the measure against the peak load while performing the overcurrent protecting operation.
  • VOL reaches VOLS through the overload protecting operation, and then the reference voltage source 13 D shows a first reference voltage VX 1 .
  • the voltage at the reference voltage source 13 D changes to a second reference voltage VX 2 lower than the first reference voltage.
  • the starting signal UV changes from the “H” state to the “L” state through the stop of the switching operation, and then the output signal of the NAND circuit 14 S changes from the “L” state to the “H” state.
  • the P-type MOSFET 14 J is turned OFF and the N-type MOSFET 14 Q is turned ON, following which the current IOL charged at the capacitor 34 is discharged. Thereafter, the switching operation is kept in the stop state until VOL decreases to the specified voltage.
  • FIG. 6 is a circuit diagram of a semiconductor device for controlling a switching power supply included in a switching power supply unit according to a second embodiment of the invention.
  • the internal circuit of the semiconductor device 30 shown in FIG. 1 is illustrated in detail, and since reference numerals correspond with those shown in FIG. 1 , the explanation of the same component is omitted.
  • a difference between the configurations shown in FIGS. 6 and 2 is in components in the feedback signal control circuit. That is, as shown in FIG. 6 , the feedback signal control circuit 11 Y is provided with a comparator 11 D and a reference voltage source 11 E, the output signal VFBO of the feedback signal control circuit 11 Y is input to the comparator 11 D, and the output signal of the comparator 11 D is input to the overload protection delay time control circuit 14 .
  • FIG. 7 is a circuit diagram of a semiconductor device for controlling a switching power supply included in a switching power supply unit according to a third embodiment of the invention.
  • the internal circuit of the semiconductor device 30 shown in FIG. 1 is illustrated in detail, and since reference numerals correspond with those shown in FIG. 1 , the explanation of the same component is omitted.
  • the overload signal output circuit 13 Y is provided with a RS flip flop 13 E which receives the output signal of the comparator 13 A as a set signal. Furthermore, the RS flip flop 13 E receives a reset signal VDDreset as an input. VDDreset refers to a reset signal from a component which does output when the input voltage used as power supply decreases, and then the terminal voltage VDD decreases below the specified voltage.
  • the switching power supply unit and the semiconductor device for the switching power supply unit according to the invention have the effects of concurrently enabling the function of the overload protector operating against the overload continued under the normal load and the continued switching operation while performing the overcurrent protection for a fixed peak-load time period, so that they are useful.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)
US11/180,702 2004-07-20 2005-07-14 Switching power supply unit and semiconductor device for switching power supply Expired - Fee Related US7116564B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2004211779A JP4064377B2 (ja) 2004-07-20 2004-07-20 スイッチング電源装置およびスイッチング電源用半導体装置
JP2004-211779 2004-07-20

Publications (2)

Publication Number Publication Date
US20060018136A1 US20060018136A1 (en) 2006-01-26
US7116564B2 true US7116564B2 (en) 2006-10-03

Family

ID=35656933

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/180,702 Expired - Fee Related US7116564B2 (en) 2004-07-20 2005-07-14 Switching power supply unit and semiconductor device for switching power supply

Country Status (2)

Country Link
US (1) US7116564B2 (ja)
JP (1) JP4064377B2 (ja)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060093017A1 (en) * 2004-10-13 2006-05-04 Infineon Technologies Ag Drive circuit for a switch in a switching converter
US20060198168A1 (en) * 2005-03-07 2006-09-07 Fuji Electric Device Technology Co., Ltd. Control method for switching power supply circuit
US20060198167A1 (en) * 2005-03-07 2006-09-07 Sanken Electric Co., Ltd. Switching power supply
US20070007938A1 (en) * 2005-07-11 2007-01-11 Djenguerian Alex B Method and apparatus to limit output power in a switching power supply
US20070019343A1 (en) * 2005-07-25 2007-01-25 Semiconductor Components Industries, Llc. Power overload detection method and structure therefor
US20070058398A1 (en) * 2005-09-15 2007-03-15 Ta-Yung Yang Start-up apparatus for power converters
US7248487B1 (en) 2006-06-01 2007-07-24 Cambridge Semiconductor Limited Switch mode power supply controllers
US20080007977A1 (en) * 2006-07-07 2008-01-10 Johan Piper Switch mode power supply systems
US20080007982A1 (en) * 2006-07-07 2008-01-10 Johan Piper Switch mode power supply systems
US20080037294A1 (en) * 2006-05-23 2008-02-14 Cambridge Semiconductor Limited Switch mode power supply controllers
US20080218663A1 (en) * 2007-03-05 2008-09-11 Sony Corporation Fluorescent tube driving method and apparatus
US20090001954A1 (en) * 2007-06-28 2009-01-01 Matsushita Electric Industrial Co., Ltd. Switching power supply
US20090116153A1 (en) * 2007-11-05 2009-05-07 Chien-Liang Lin Power conversion system and over-load protection device thereof
US20090147547A1 (en) * 2007-12-07 2009-06-11 Panasonic Corporation Energy transfer device and energy transfer control semiconductor device
US20090153207A1 (en) * 2007-12-12 2009-06-18 Kraft Jonathan P Method of forming a pwm controller and structure therefor
US20100124081A1 (en) * 2008-11-19 2010-05-20 Panasonic Corporation Switching power supply
US20100315841A1 (en) * 2009-06-11 2010-12-16 Panasonic Corporation Semiconductor device and switching power supply apparatus
US20110221267A1 (en) * 2008-10-01 2011-09-15 Robert Bosch Gmbh Voltage Supply
US20120044724A1 (en) * 2009-04-27 2012-02-23 Panasonic Corporation Switching power supply apparatus
US20130128627A1 (en) * 2011-11-23 2013-05-23 Fairchild Korea Semiconductor Ltd. Switch control method, switch controller, and converter comprising the switch controller
US20150048755A1 (en) * 2012-03-26 2015-02-19 Sharp Kabushiki Kaisha Switching power supply circuit and led illumination device
RU2581612C1 (ru) * 2012-08-03 2016-04-20 Абб Текнолоджи Аг Ограничение перегрузки при работе с пиковой мощностью
US11336170B2 (en) * 2018-03-13 2022-05-17 Fuji Electric Co., Ltd. Frequency setting in a power supply device, power supply control device, and power supply control method

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4059223B2 (ja) * 2004-03-31 2008-03-12 ブラザー工業株式会社 電源装置及び画像形成装置
JP4867500B2 (ja) * 2006-06-29 2012-02-01 富士電機株式会社 スイッチング電源装置
JP4952936B2 (ja) * 2007-10-23 2012-06-13 サンケン電気株式会社 スイッチング方式ｄｃｄｃコンバータ
JP5353119B2 (ja) * 2008-08-26 2013-11-27 サンケン電気株式会社 スイッチング電源装置
KR101067923B1 (ko) 2009-03-25 2011-09-26 주식회사 케이이씨 소프트 스타트 및 과부하 보호 기능을 갖는 스위칭 모드 파워 서플라이
US8405456B2 (en) 2009-03-31 2013-03-26 Quantance, Inc. High speed power supply system
WO2011116225A1 (en) * 2010-03-17 2011-09-22 Power Systems Technologies, Ltd. Control system for a power converter and method of operating the same
US9214804B2 (en) * 2010-11-11 2015-12-15 Telefonaktiebolaget L M Ericsson (Publ) Overload detection in a switched mode power supply
US8792257B2 (en) 2011-03-25 2014-07-29 Power Systems Technologies, Ltd. Power converter with reduced power dissipation
EP2792037A2 (en) * 2011-12-14 2014-10-22 Cirrus Logic, Inc. Multi-mode flyback control for a switching power converter with dimmer
US8792256B2 (en) 2012-01-27 2014-07-29 Power Systems Technologies Ltd. Controller for a switch and method of operating the same
US8952753B2 (en) 2012-02-17 2015-02-10 Quantance, Inc. Dynamic power supply employing a linear driver and a switching regulator
US8890502B2 (en) 2012-02-17 2014-11-18 Quantance, Inc. Low-noise, high bandwidth quasi-resonant mode switching power supply
US9190898B2 (en) 2012-07-06 2015-11-17 Power Systems Technologies, Ltd Controller for a power converter and method of operating the same
US9240712B2 (en) 2012-12-13 2016-01-19 Power Systems Technologies Ltd. Controller including a common current-sense device for power switches of a power converter
KR102127532B1 (ko) * 2013-10-31 2020-06-26 솔루엠 (허페이) 세미컨덕터 씨오., 엘티디. 집적 회로
US9300206B2 (en) 2013-11-15 2016-03-29 Power Systems Technologies Ltd. Method for estimating power of a power converter
DE102015114495A1 (de) * 2015-08-31 2017-03-02 Infineon Technologies Austria Ag Spannungswandler und spannungswandlungsverfahren
JP6812550B2 (ja) 2017-09-22 2021-01-13 オッポ広東移動通信有限公司Ｇｕａｎｇｄｏｎｇ Ｏｐｐｏ Ｍｏｂｉｌｅ Ｔｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓ Ｃｏｒｐ．， Ｌｔｄ． 電源供給回路、電源供給機器および制御方法
CN107943198B (zh) * 2017-12-26 2024-03-15 上海新进芯微电子有限公司 一种开关电压输出电流的检测电路及开关电源***
US11188105B2 (en) * 2018-10-10 2021-11-30 Smart Prong Technologies, Inc. Electrical circuit for pre-regulation power management
TWI684087B (zh) * 2019-03-11 2020-02-01 聚積科技股份有限公司 穩壓系統

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0638518A (ja) 1992-07-13 1994-02-10 Yokogawa Electric Corp 電源の過電流保護回路
US6674656B1 (en) * 2002-10-28 2004-01-06 System General Corporation PWM controller having a saw-limiter for output power limit without sensing input voltage
US6879501B2 (en) * 2002-05-13 2005-04-12 Matsushita Electric Industrial Co., Ltd. Switching power supply
US6958920B2 (en) * 2003-10-02 2005-10-25 Supertex, Inc. Switching power converter and method of controlling output voltage thereof using predictive sensing of magnetic flux
US6980444B2 (en) * 2003-10-09 2005-12-27 Matsushita Electric Industrial Co., Ltd. Switching power supply
US7035119B2 (en) * 2002-08-30 2006-04-25 Sanken Electric Co., Ltd. Switching power source device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0638518A (ja) 1992-07-13 1994-02-10 Yokogawa Electric Corp 電源の過電流保護回路
US6879501B2 (en) * 2002-05-13 2005-04-12 Matsushita Electric Industrial Co., Ltd. Switching power supply
US7035119B2 (en) * 2002-08-30 2006-04-25 Sanken Electric Co., Ltd. Switching power source device
US6674656B1 (en) * 2002-10-28 2004-01-06 System General Corporation PWM controller having a saw-limiter for output power limit without sensing input voltage
US6958920B2 (en) * 2003-10-02 2005-10-25 Supertex, Inc. Switching power converter and method of controlling output voltage thereof using predictive sensing of magnetic flux
US6980444B2 (en) * 2003-10-09 2005-12-27 Matsushita Electric Industrial Co., Ltd. Switching power supply

Cited By (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7468896B2 (en) * 2004-10-13 2008-12-23 Infineon Technologies Ag Drive circuit for a switch in a switching converter
US20060093017A1 (en) * 2004-10-13 2006-05-04 Infineon Technologies Ag Drive circuit for a switch in a switching converter
US7242596B2 (en) * 2005-03-07 2007-07-10 Fuji Electric Device Technology Co., Ltd. Control method for switching power supply circuit
US20060198168A1 (en) * 2005-03-07 2006-09-07 Fuji Electric Device Technology Co., Ltd. Control method for switching power supply circuit
US20060198167A1 (en) * 2005-03-07 2006-09-07 Sanken Electric Co., Ltd. Switching power supply
US7388763B2 (en) * 2005-03-07 2008-06-17 Sanken Electric Co., Ltd. Switching power supply
US7215107B2 (en) * 2005-07-11 2007-05-08 Power Integrations, Inc. Method and apparatus to limit output power in a switching power supply
US7359225B2 (en) 2005-07-11 2008-04-15 Power Integrations, Inc. Method and apparatus to limit output power in a switching power supply
US20070007938A1 (en) * 2005-07-11 2007-01-11 Djenguerian Alex B Method and apparatus to limit output power in a switching power supply
US20070176589A1 (en) * 2005-07-11 2007-08-02 Djenguerian Alex B Method and apparatus to limit output power in a switching power supply
US8587284B2 (en) 2005-07-11 2013-11-19 Power Integrations, Inc. Method and apparatus to limit output power in a switching power supply
US8143875B2 (en) 2005-07-11 2012-03-27 Power Integrations, Inc. Method and apparatus to limit output power in a switching power supply
US20090256544A1 (en) * 2005-07-11 2009-10-15 Power Integrations, Inc. Method and apparatus to limit output power in a switching power supply
US20080164858A1 (en) * 2005-07-11 2008-07-10 Power Integrations, Inc. Method and apparatus to limit output power in a switching power supply
US7990125B2 (en) 2005-07-11 2011-08-02 Power Integrations, Inc. Method and apparatus to limit output power in a switching power supply
US20070019343A1 (en) * 2005-07-25 2007-01-25 Semiconductor Components Industries, Llc. Power overload detection method and structure therefor
US7679874B2 (en) * 2005-07-25 2010-03-16 Semiconductor Components Industries, L.L.C. Power overload detection method and structure therefor
US20070058398A1 (en) * 2005-09-15 2007-03-15 Ta-Yung Yang Start-up apparatus for power converters
US7257008B2 (en) * 2005-09-15 2007-08-14 System-General Corporation Start-up apparatus for power converters
US20080037294A1 (en) * 2006-05-23 2008-02-14 Cambridge Semiconductor Limited Switch mode power supply controllers
US7499295B2 (en) 2006-05-23 2009-03-03 Cambridge Semiconductor Limited Switch mode power supply controllers
US7248487B1 (en) 2006-06-01 2007-07-24 Cambridge Semiconductor Limited Switch mode power supply controllers
US7342812B2 (en) 2006-07-07 2008-03-11 Cambridge Semiconductor Limited Switch mode power supply systems
US7583519B2 (en) 2006-07-07 2009-09-01 Cambridge Semiconductor Limited Switch mode power supply systems
US20080137380A1 (en) * 2006-07-07 2008-06-12 Cambridge Semiconductor Limited Switch mode power supply systems
US20080007982A1 (en) * 2006-07-07 2008-01-10 Johan Piper Switch mode power supply systems
US20080007977A1 (en) * 2006-07-07 2008-01-10 Johan Piper Switch mode power supply systems
US20080218663A1 (en) * 2007-03-05 2008-09-11 Sony Corporation Fluorescent tube driving method and apparatus
US20090001954A1 (en) * 2007-06-28 2009-01-01 Matsushita Electric Industrial Co., Ltd. Switching power supply
US7778049B2 (en) * 2007-06-28 2010-08-17 Panasonic Corporation Switching power supply
US20090116153A1 (en) * 2007-11-05 2009-05-07 Chien-Liang Lin Power conversion system and over-load protection device thereof
US20090147547A1 (en) * 2007-12-07 2009-06-11 Panasonic Corporation Energy transfer device and energy transfer control semiconductor device
US7778050B2 (en) 2007-12-07 2010-08-17 Panasonic Corporation Energy transfer device and energy transfer control semiconductor device
CN101459384B (zh) * 2007-12-12 2013-08-28 半导体元件工业有限责任公司 形成pwm控制器的方法及其结构
US7961485B2 (en) * 2007-12-12 2011-06-14 Semiconductor Components Industries, Llc Method of forming a PWM controller and structure therefor
US20090153207A1 (en) * 2007-12-12 2009-06-18 Kraft Jonathan P Method of forming a pwm controller and structure therefor
US20110221267A1 (en) * 2008-10-01 2011-09-15 Robert Bosch Gmbh Voltage Supply
US8767412B2 (en) * 2008-10-01 2014-07-01 Robert Bosch Gmbh Voltage supply
US20100124081A1 (en) * 2008-11-19 2010-05-20 Panasonic Corporation Switching power supply
US20120044724A1 (en) * 2009-04-27 2012-02-23 Panasonic Corporation Switching power supply apparatus
US8339816B2 (en) * 2009-06-11 2012-12-25 Panasonic Corporation Semiconductor device and switching power supply apparatus
US20100315841A1 (en) * 2009-06-11 2010-12-16 Panasonic Corporation Semiconductor device and switching power supply apparatus
US20130128627A1 (en) * 2011-11-23 2013-05-23 Fairchild Korea Semiconductor Ltd. Switch control method, switch controller, and converter comprising the switch controller
US9312774B2 (en) * 2011-11-23 2016-04-12 Fairchild Korea Semiconductor Ltd. Switch control method, switch controller, and converter comprising the switch controller
US20150048755A1 (en) * 2012-03-26 2015-02-19 Sharp Kabushiki Kaisha Switching power supply circuit and led illumination device
US9263957B2 (en) * 2012-03-26 2016-02-16 Sharp Kabushiki Kaisha Switching power supply circuit and LED illumination device
RU2581612C1 (ru) * 2012-08-03 2016-04-20 Абб Текнолоджи Аг Ограничение перегрузки при работе с пиковой мощностью
US11336170B2 (en) * 2018-03-13 2022-05-17 Fuji Electric Co., Ltd. Frequency setting in a power supply device, power supply control device, and power supply control method

Also Published As

Publication number Publication date
JP4064377B2 (ja) 2008-03-19
JP2006034045A (ja) 2006-02-02
US20060018136A1 (en) 2006-01-26

Similar Documents

Publication Publication Date Title
US7116564B2 (en) Switching power supply unit and semiconductor device for switching power supply
US6980444B2 (en) Switching power supply
US7492615B2 (en) Switching power supply
US7787269B2 (en) Switching power supply device
JP6424644B2 (ja) 電源制御用半導体装置
US7778049B2 (en) Switching power supply
JP4481879B2 (ja) スイッチング電源装置
US7535736B2 (en) Switching power supply for reducing external parts for overcurrent protection
US7388763B2 (en) Switching power supply
JP6597239B2 (ja) スイッチング電源装置
JP3652351B2 (ja) スイッチング電源装置
US9231483B2 (en) DC/DC converter
US7259973B2 (en) Semiconductor apparatus for controlling a switching power supply
US20100124081A1 (en) Switching power supply
TW201225495A (en) Shunt regulator, flyback converter and control method for its output feedback
US10170906B2 (en) Semiconductor device for power supply control
US20180034373A1 (en) Semiconductor device for controlling power source
US20100033992A1 (en) Switching power supply controller and semiconductor device used for the same
US20140347895A1 (en) Switching Power-Supply Device
WO2010125751A1 (ja) スイッチング電源装置
JP4387244B2 (ja) スイッチング電源装置
JP2019047655A (ja) 電源制御用半導体装置および電源装置並びにｘコンデンサの放電方法およびスイッチ制御方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TAKAHASHI, SATORU;REEL/FRAME:016779/0542

Effective date: 20050615

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

AS Assignment

Owner name: PANASONIC CORPORATION, JAPAN

Free format text: CHANGE OF NAME;ASSIGNOR:MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.;REEL/FRAME:031947/0358

Effective date: 20081001

AS Assignment

Owner name: PANASONIC CORPORATION, JAPAN

Free format text: LIEN;ASSIGNOR:COLLABO INNOVATIONS, INC.;REEL/FRAME:031997/0445

Effective date: 20131213

REMI Maintenance fee reminder mailed
AS Assignment

Owner name: COLLABO INNOVATIONS, INC., CANADA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PANASONIC CORPORATION;REEL/FRAME:033021/0806

Effective date: 20131212

FPAY Fee payment

Year of fee payment: 8

SULP Surcharge for late payment

Year of fee payment: 7

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.)

LAPS Lapse for failure to pay maintenance fees

Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362